Biodiversity And Classification Flashcards
Biodiversity
Biodiversity is the study of living things
The full range of different living things in a region; can be described as various levels, including the
- range of species
- genetic diversity in species
- diversity of ecosystems present in a larger area.
Biodiversity is dependent on population size (larger the population - the more biodiversity)
Species diversity
A group of similar organisms which are capable of interbreeding in nature and produce viable, fertile offspring
Variety of species in an ecosystem
Each species essential services to ecosystem
Recycling of organic matter - essential service
Rainforest is a stable ecosystem
Desert is a low biodiversity - less stable
Species richness - number (abundance)
Ecosystem diversity
Composed of all living organisms (biotic factors) in one area, together with the physical environment or non - living factors (abiotic factors) and their interactions.
Ecosystem with the greatest biodiversity are more stable.
Variety within an ecosystem community and the environment
Genetic diversity
Variety of genes (alleles) in a given species
Allows populations to adapt
Favourable combinations of genes and alleles already be present in the population
Individuals do not adapt to change - it is the population or species as a whole which adapts to change
Measures of biodiversity - change
Biodiversity is constantly changing over spatial (space) and temporal (time) scales
Spatial distribution (scales)
How the space is being occupied
To understand the extent of an area and the distribution of the species within it
How the features of the landscape are arranged across the surface of the earth
Temporal distribution (scales)
Refers to time
Provide detail about the biodiversity in a certain area over a certain period of time
Populations, communities and ecosystems are constantly changing over geographical and evolutionary timescales. Changes are influenced between living (biotic) and non living (abiotic) factors
Biodiversity hotspots
Are geographic areas contain high levels of species diversity but are threatened with extinction
To qualify must contain:
- at least 1500 species of native vascular plants
- it has to have lost at least 70% of its original habitat
Three factors that usually determine hotspots
- The number of total species (species richness)
- The number of unique species (endemism)
- The number of species at risk (threat of extinction)
Importance of biodiversity
Protection of water resources
Soil formation and protection
Nutrient cycle (O2, CO2, N cycles)
Pollution breakdown and absorption
Climate stability
Maintaining ecosystems
Recovery from unpredictable events
Food and medicinal resources
Protection of water resources
Ecosystems are essential for the water cycle
Natural vegetation stops water run off and regulate water table
Soil formation and protection
Vegetation prevents landslides
Root systems bring nutrients to the surface
Decaying matter return nutrients to soil
Nutrient cycle (O2, CO2, N cycles)
All parts of ecosystems are essential for nutrient cycling
Pollution breakdown and absorption
Bacteria breakdown much of the human waste and pollution
Wetland areas are particularly good at removing pollutants
Climate stability
Rainforests regulate nearby water vapour levels and humidity
Maintaining ecosystems
A change in one factor in an ecosystem can instruct and destroy the whole system
Recovering from unpredictable events
Less biodiversity means less ability to recover and regenerate from an event like a cyclone, fire
Food and medicinal resources
Human life and activities are heavily dependent on the natural environment
5000 plant species have been used by humans for food
Most drugs are derived from plants or bacterial species
8 Taxa - levels of classification
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Domain
Bacteria - unicellular prokaryotes (no nucleus or membrane - bound organelles)
Archaea - unicellular prokaryotes (no nucleus or membrane - bound organelles)
Eukarya - are more complex and have a nucleus and membrane - bound oganelles
Kingdom
Animalia - includes mammals, insects and sea sponges
Plantae - includes mosses, ferns and flowering plants
Protista - includes amoebae
Fungi - includes yeasts, moulds and mushrooms
Archaea - microscopic single-called organisms known for living in extreme environments
Bacteria - microscopic single-celled organisms
Classification and taxonomy
Classification is the grouping together of organisms that have similar features
The science of naming and classifying organisms is known as taxonomy
A taxonomy is a group of organisms in a classification system
Why do we classify organisms
Helps us
- identify them
- work out their evolutionary relationships
- preserve them
International classification system means everyone can use it and understand it
Linnaeus classification
Linnaeus grouped organisms according to their structural similarities
Linnaeus used a hierarchy system
Two kingdoms at the top - (plants and animals) and thousands at the bottom
The Linnaean system is called binomial nomenclature
Why do we study biodiversity
- Ecosystems processes are essential to survival
- dependent on photosynthesis - converting light energy to chemical energy - Biodiversity delivers educational and cultural benefits
- Biodiversity contributes to the production of food, purified water and air, fibre products such as wool and cotton, fuels, climate control and pharmaceuticals
- Biodiversity attracts tourism and contributes to the economy
Biological species concept
A species is a group of organisms who are able to interbreed in nature and produce viable, fertile offspring
Morphological species concept
This concept characteristics a species by its form, or morphology
Phylogenetic species concept
Identifies a species as being the smallest group of organisms who can all trace their origins to a single common ancestor
The binomial system
All organisms have a binomial (specific) name
Binomial names consist of two parts: the first denotes the genus and the second is specific to the species
In the binomial system for naming species
The genus name has the first letter capitalised
The species name is not capitalised
When hand written - underlined
When in print - italics
Classification
Classification is based on the idea that members of the same group share characteristics that are not present in members outside the group
The animal kingdom
Is made up of organisms that share similar phylogeny, morphology and molecular data
The animals kingdom is classified into 36 phyla, with most species placed in nine of these phyla
Vascular tissue
Comprised of phloem and xylem
- which are tubes of connected cells that transport nutrients and water through the plants
Members of the plant kingdom
Are eukaryotic, photosynthetic and often terrestrial.
They are classified by whether or not they contain vascular tissue, and whether they reproduce by spores, cones or flower
Classification keys
Tools used by scientists to identify organisms that belong to species that have already been discovered
Physical characteristics about the habitat or organism
Dichotomous keys
Dichotomous keys are tools used to identify organisms. They involve choosing between a series of two options until an organism is identified
Dichotomous key for identifying
As a diagram
Dichotomous key for classifying
Using descriptive sentences
Cladistics - cladograms
Organisms are classified into groups that reflect their evolutionary history. This classification is based on the fact that related organisms share characteristics. Evolutionary relationships can be visualised using phylogenetic trees
Common ancestor
An ancestor that two or more descendants have in common
clade
Each taxonomy group contains all of the organisms descended from the same common ancestor. This means that a group on a cladogram contains all of the organisms on a branch. When this occurs, that group is called a clade (or its members can be referred to as monophyletic)
New technologies & taxonomy
Transformed cladistics & taxonomy
